Device for producing hot water or steam on demand using a single distribution control member

ABSTRACT

The present invention concerns steam generators and a heating unit consisting of a tube (21) for circulating water in a connecting column (3) arranged below a reservoir (1). The heating unit is characterized by having two parts (A, B) each including a portion of the circulating tube (21) to form two heating areas, the first part (A) being slightly angled and extending downwards from the connecting column (3) in the direction of the water flow, the second part (B) extending upwards to convey water to the dispensing member (10). Application to coffee machine boilers.

BACKGROUND OF THE INVENTION

The present invention relates to the field of appliances intended tofurnish hot water and/or steam for different operations such as thepreparation of hot beverages, cleaning, pressing or cooking. Theinvention concerns more particularly the structure and operation of awater heater or heating unit, arranged for example, in a coffee maker ofthe filter of espresso type. Other appliances such as steam generators,pressing irons or steam cookers are equally concerned and do not falloutside of the framework of the present invention.

It is already known, and particularly from the document EP-A-0432460 tomake water heaters, for hot beverage machines, in a particular form, inorder to transfer and heat the water with an improved efficiency. Thewater heater described in this prior art document comprises a heatingelement in thermal communication with a water circulation pipe. Theheating element and the pipe have a form substantially in a U withvertical inlet and outlet portions and an intermediate portion which isslightly inclined and rises relative to the horizontal in the directionof water circulation. In addition, the heating element comprises fourheating zones which are differentiated and distributed along the watercirculation pipe. Such a conception permits in particular evacuationtoward the outlet portion of vapor bubbles while preventing their returntoward the inlet portion of the pipe.

The drawbacks of a water heater such as described in the documentEP-A-0432460 is on the one hand the impossibility of utilizing saidwater heater to produce hot water or vapor as desired by the user and onthe other hand a complexity of fabrication or production which increasesits cost.

BRIEF SUMMARY OF THE INVENTION

The object of the present invention is to produce a water heater free ofthe drawbacks of the prior art and permitting an increase in performanceas much with respect to the temperature obtained for the hot water aswith respect the speed of preparation of beverages or of production ofsteam. Such a heating unit equally has for its object to increase theduration of the presence of a large part of the water in a water heater,in a manner to optimize the temperature of all of the hot waterdistributed.

Another object of the present invention is to furnish a heating unitpermitting the distribution of hot water or steam as desired by theuser.

A supplemental object of the present invention is to produce a heatingunit permitting the distribution of either hot water or steam with alimited number of parts and thus to reduce the cost of such a device.

The objects assigned to the invention are achieved with the aid of aheating unit for a household appliance constituted by a watercirculation pipe in thermal communication with a heating element,permitting transfer of water contained in a reservoir toward adistribution member, and through respectively a connection columndisposed below the reservoir and the circulation pipe presenting aconfiguration in two parts associated with a portion of a heatingelement, the second part extending upwardly to bring the water towardthe distribution member, characterized in that the first part, orientedat an angle with respect to the second part, extends between theconnection column furnished with a non-return valve and said secondpart, in an inclined manner and descending in the direction of flow ofthe water.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The characteristics and advantages of the invention will become morereadily apparent from a reading of the description given below withreference to the attached drawings given by way of non-limiting examplein which:

FIG. 1 represents an overall view in cross-section of a heating unitaccording to the invention,

FIG. 2 represents a cross-section of a part of the heating unitaccording to the invention,

FIG. 3 represents a construction variation of the heating unit accordingto the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 represents an overall view in cross-section of the heating unitaccording to the invention, and permits at the same time visualizationof the operation of said heating unit. The heating unit comprises areservoir 1, a distribution member 10, a water heater 20 as well asmeans for connecting together the different elements. Reservoir 1 forstoring water is arranged, fixed or housed by any means at the interiorof the appliance for preparation of hot beverages for example.

Reservoir 1 comprises a bottom 1a in which is arranged an opening 2 toevacuate water stored in said reservoir 1, during operation of theheating unit. Opening 2 opens into a connection column 3 in which isarranged a non-return valve 4. Connection column 3 presents a tubularform with an internal diameter preferably of around 10 millimeters.Connection column 3 is also in communication with the water heater 20.

In the embodiment represented in FIG. 1, the connection column 3communicates with the water heater 20 by the intermediary of a piece 3chaving a bent form. Connection column 3 is also constituted by avertical part preferably containing the non-return valve 4. Thesubstantially horizontal portion of the bent form 3c comes to be fixedon an extremity of the water heater 20 in a manner permitting thetransfer of the water contained in reservoir 1 and in connection column3 towards said water heater 20. Connection column 3 presents a height hpreferably comprised between 90 and 120 millimeters. Such a height hpermits a sufficient force to be given to the water contained in theconnection column 3 to penetrate into the water heater 20 when thenon-return valve 4 is opened. Operation noises, as well as the steamproduced are thus reduced when reservoir 1 is almost empty. Height h isadvantageously defined by the distance taken vertically and separating ahorizontal line drawn from bottom 1a of reservoir 1 and an axis x-x'defined by water heater 20. The distance defined by height h islocalized at the inlet of water heater 20.

Connection column 3 is for example, constituted of a silicone hose.Water heater 20 is constituted by a circulation pipe 21 in thermalcommunication with a heating element 22 to permit the transfer of watercontained in reservoir 1 through said circulation pipe 21 toward adistribution member 10. Water heater 20 represented in FIGS. 1 and 2presents a configuration which can be described by the intermediary of adistinction made between a first part A and a second part Bcorresponding to said configuration. First part A and second part Bextend in directions oriented angularly with respect to one another.

Second part B is rising in order to bring the water toward distributionmember 10 and first part A extends between the rising second part B andconnection column 3. First part A is also slightly inclined and risingin the direction opposite to the flow of water, i.e., toward connectioncolumn 3. First part A extends along axis x-x' presenting with respectto its orthogonal projection on a horizontal plane, an inclination equalto or greater than 4° and preferably comprised between 5° and 10°. Anorthogonal projection on a horizontal plane is defined as a horizontalline. In addition, second part B presents an inclination with an angle βwith respect to its orthogonal projection on a horizontal plane, forexample, comprised between 45° and 135° and preferably comprised between45° and 100°.

FIG. 2 advantageously represents a vertical extension plane defined byfirst part A and second part B, said extension plane having to behowever considered in space. The extension plane defined by first part Aand second part B is for example inclined with respect to an imaginaryvertical plane containing a first part A, with an angle preferablycomprised between 0° and 45°.

FIG. 2 represents the preferred inclinations of circulation pipe 21 ofwater heater 20. Thus, second part B extends along a vertical axis y-y'and first part A extends along an inclined axis x-x' at an angle withrespect to its horizontal line. Angle a is greater than or equal to 4°and preferably between 5° and 10°.

According to one embodiment of the heating unit according to theinvention, second part B extends along an axis y-y' presenting aninclination with respect to its horizontal line comprised between 45°and 135° and preferably comprised between 45° and 100°. It is obviousthat heating element 22 presents the same configuration as circulationpipe 21 in a manner to be in intimate thermal communication along theentirety of its length with said circulation pipe 21. Extremities 22aand 22b of heating element 21 advantageously present an inclinationwhich departs from circulation pipe 21 in order to facilitate theattachment of the electrical connections which are not shown in thefigure.

According to another mode of construction of the heating unit accordingto the present invention and shown in FIG. 3, at least one of parts Aand B has a curved form defined by at least one radius of curvature. Theheating unit can also comprise straight line segments and curvedsegments in combination to take up a space adapted to the appliance onwhich the heating unit is mounted. Advantageously, imaginary straightline portions can be defined to satisfy the preferential inclinationsaccording to the present invention. Thus, a point O is defined at thetangent point of circulation pipe 21 with respect to a horizontal plane.Points I and J are defined by the center of a transverse section ofcirculation pipe 21 located at levels corresponding to the extremitiesof heating element 22, said extremities being in direct thermal contactwith circulation pipe 21.

Imaginary segments OJ and OI are thus assimilated respectively to firstpart A and second part B.

Water heater 20 is constituted by two metallic tubes in thermalcommunication, one of which constitutes circulation pipe 21 utilized forthe circulation of water, the other metallic tube serving as a housingfor heating element 22.

According to another form of construction of the heating unit accordingto the invention, heating element 22 can be fixed or secured tocirculation pipe 21 by any known means and particularly by soldering.

Advantageously, circulation pipe 21 extends along axis x-x' beyond theextremity of heating element 22 in order to realize a portion ofcirculation pipe 21 heated by thermal conduction. Circulation pipe 21thus comprises, beyond second part B, a length portion C heated solelyby thermal conduction by second part B. Heating element 22 is preferablyconstituted by a sheathed heating element. This latter, in thermalrelation with circulation pipe 21 presents a uniform thermal yield alongthe entirety of its length. Non-return valve 4 known per se isconstituted for example of a spherical ball 4c moveable in translationbetween two stops 4a and 4b against which it comes to a block. Whenspherical ball 4c is in its upper position against stop 4a, a flow ofwater in connection column 3 toward water heater 20 is interrupted andwhen spherical ball 4c is in its lower position against stop 4b, a flowof water is permitted by a specific and known configuration of said stop4b. Circulation pipe 21 also comprises at its extremity a connectionmember 24 permitting transfer of water from water heater 20 towarddistribution member 10. Connection member 24 advantageously has the sameinternal diameter as circulation pipe 21 and connection column 3.

Heating element 22 is in thermal communication with circulation pipe 21in first part A on a proportion of the length of heating element 22which is less than the proportion of the length of heating element 22 inthermal communication with circulation pipe 21 in second part B. Thedistribution of thermal transfer between heating element 22 andcirculation pipe 21 corresponds to values comprised between 35% and 45%in first part A and values comprised between 55% and 65% in second partB.

Advantageously, the distribution of thermal transfer between heatingelement 22 and circulation pipe 21 corresponds respectively to 40% and60% in first part A and second part B. Such a thermal distributionparticularly permits water expelled from water heater 20 to achieve atemperature of 90° C. during all of the phase of production of hotwater.

According to another form of construction of the heating unit accordingto the invention, the distribution of thermal transfer between heatingelement 22 and circulation pipe 21 corresponds in first part A to avalue comprised between 20% and 30% of the total thermal transfer. Waterheater 20 is in this form of construction according to the invention andcomposed of four zones, of which the first pseudo-horizontal correspondsto first part A and the second corresponds to a bent part forming theconnection between first part A and the second part B. This later,rising, corresponds then to the third zone. The width portion C, heateduniquely by conduction, can advantageously be assimilated to a forthzone of water heater 20. The thermal transfer existing in the second andthe third zone thus defined correspond substantially to a range of 70%to 80% of the total thermal transfer. The distribution of this thermaltransfer between the second zone and the third zone is not ofimportance.

The heating unit according to the invention also comprises a thermostat30 for thermal regulation of which a fixation and thermal transfer footis arranged on water heater 20 preferably in an interface zone betweenfirst part A and second part B. In addition, the heating zonecorresponding to second part B extends to a horizontal levelcorresponding to the level defined approximately by bottom 1a ofreservoir 1. Thus, all of the water contained in water heater 20, andthe length portion C are heated, as soon as heating element 22 issupplied. Only a possible small quantity of water, found in connectionnumber 20 before start of operation of the heating unit has a weakerheating, when the material constituting connection member 24 is not athermal conductor.

Distribution member 10 into which empties connection member 24 presentsat least two expulsion paths one of which in intended for hot water andthe other of which for steam. The heating unit thus comprises meanspermitting it to produce and distribute hot water or vapor due to acontrol member 13 operated by the user. Thus, distribution member 10comprises a first orifice 11 allowing escape of hot water by gravity anda second orifice 12 presenting a stricture 12a permitting production ofsteam starting from the water contained in circulation pipe 21.Distribution member 10 is also constituted by control member 13permitting connection member 24 to be placed in communication with firstorifice 11 or second orifice 12.

According to an example of a form of construction of the heating unitaccording to the invention, control member 13 is constituted by a shank13a for example metallic displaceable by translation in a cylindricalbody 14. Rigid shank 13a also comprises two discs 13b and 13c spacedapart and extending in extension planes perpendicular to said rigidshank 13a in a manner to create a piston displaceable by translation incylindrical body 14. Discs 13c and 13b have a diameter substantiallysimilar to the internal diameter of cylindrical body 14. Discs 13c and13b equally present around all of their periphery a housing for asealing joint 15 permitting the different compartments thus created incylindrical body 14 to be rendered fluid tight. FIG. 1 shows forexample, control member 13 in a position adapted to allow hot water toescape by gravity through first orifice 11. The dotted lines representdiscs 13c and 13b when control member 13 in a position adapted to placeconnection member 24 in communication with second orifice 12 through acompartment defined between discs 13b and 13c in hollow body 14. Thislatter position corresponds to a regulation of control member 13 toproduce steam starting from water contained in water heater 20.Cylindrical body 14 equally comprises a safety valve 16 when oneutilizes the heating unit according to the invention to produce steam.Safety valve 16 is advantageously arranged on the part of cylindricalbody 14 in which steam pressure is established.

The heating unit according to the invention also comprises clampingcollars 3a, 3b, 5a, 21a and 24a in the assembly zones of the differenttubular elements constituting a conduit for leading water from reservoir1 and if need be steam from water heater 20 toward distribution member10. Fluid tightness and pressure resistance are thus assured. Theassembly and the tightening of said clamping collars 3a, 3b, 5a, 21a and24a on the tubular elements are carried out by any known means. Clampingcollar 3b is utilized to prevent non-return valve 4 from being displacedin connection column 3.

According to another form of construction of the heating unit accordingto the invention, distribution member 10 is constituted by a gatecomprising at least 3 paths, susceptible to place circulation pipe 21 incommunication either with first orifice 11 or with second orifice 12.Such a gate is constituted for example by ceramic discs provided withdifferent orifices capable of coming in line with one another to placein communication different paths of circulation of hot water or ofsteam. According to a form of construction of the heating unit accordingto the invention, the dimensions of first part A and the second part Bare respectively 75 millimeters and 100 millimeters. The power ofheating element 22 is comprised between 500 and 1,200 watts. For theproduction of hot water, the power is comprised preferably between 1,000and 1,200 watts and for the production of steam, the power is comprisedpreferably between 500 and 600 watts.

The heating unit according to the invention thus permits obtaining apreferential operation either during the production of hot water orduring the production of steam. Before placing the heating unit intooperation, i.e., before supplying electricity to heating element 22,part of the water contained in reservoir 1 flows past non-return valve 4under the effect of its weight and flows into water heater 20. The levelof water obtained in second part B or in length portion C or inconnection member 24 is determined by the principal of communicatingvessels. Thus, the fact of constructing water heater 20 with heatingelement 22 of which extremity 22b extends up to a level in the vicinityof bottom 1a on the one hand, and with a length portion C heated bythermal conduction permits a reduction and even a suppression of theexistence of a quantity of cold water expelled by distribution member 10at the start of operation of the heating unit. When heating element 22is supplied with an electric current it produces a first heating andthus a slight evaporation in first part A with bubbles of steam beingdisplaced in the direction of non-return valve 4. There is thusestablished in the zone situated below non-return valve 4 a pressurecausing ball 4c to move upwardly into abutment against stop 4a in amanner to block the water passage and prevent the arrival of asupplemental quantity of water into water heater 20. Thermal dissipationby heating element 22 then contributes to a more and more substantialheating of the water contained in second part B as well as in first partA to create a sufficient pressure which permits the water to be causedto rise toward connection member 24 and to be evacuated by first orifice11 of distribution member 10. First orifice 11 presents for this purposea dimension or diameter greater than the internal diameter ofcirculation pipe 21. Second part B i.e., the rising portion of waterheater 20, permits creation of a sufficient pressure in aiding theappearance of vapor bubbles having a larger volume and a highertemperature. When a part of the water contained in a portion of part Bin water heater 20 is evacuated via first orifice 11, there is created aslight pressure drop in water heater 20 and above all at the level ofnon-return valve 4. Ball 4c is drawn toward the bottom against stop 4bin a manner to permit a small quantity of water from reservoir one toreach water heater 20.

The same phenomenon is reproduced in small cycles and with smallquantities of water until reservoir 1 empties. Aspiration of a smallquantity of water during each cycle corresponding to expulsion ofanother quantity of water from water heater 20 permits avoidance of anexpulsion of cold or tepid water from water heater 20 after the firstoperating cycle. The water thus aspirated or admitted into water heater20 after the first operation cycle is found mixed with already hot watercontained in said water heater 20. Thus, no water having an insufficienttemperature is distributed by the heating unit during operation. Theinclination of metallic tube 21 in first part A permits a displacementin the direction of non-return valve 4 of vapor bubbles produced in thissame first part A to block the arrival of water and aid the expulsion ofwater from water heater 20.

When the user decides to produce steam he selects with the aid of thecontrol member 13 the steam position which corresponds to the blockingof first orifice 11 and the placing of connection number member 24 incommunication with second orifice 12 of distribution member 10. Secondorifice 12 is connected to a stricture 12a presenting for example anexpulsion diameter of 1.4 millimeters. The diameter of stricture 12a isthus obviously a function of the power with which steam is produced.Stricture 12a is an obstacle braking the expulsion of water contained inwater heater 20. This obstacle to flow leads to a longer duration ofpresence of water in water heater 20 and thus provokes a moresubstantial heating of said water. This latter provokes a moresubstantial vaporization and consequently a production of steam. Thisproduction of steam increases the pressure at the interior of waterheater 20 in a manner to block by the intermediary of non-return valve 4the arrival of new quantities of cold water from reservoir 1. Theblocking of connection column 3 continues until nearly completeevaporation of the water contained in water heater 20. The pressureexisting at the interior of water heater 20 permits complete evacuationof water in the vapor phase and provokes as a result a displacement ofball 4c in order to aspirate by pressure drop a quantity of waterfilling first part A and at least partially second part B of circulationpipe 21 of water heater 20. The water evacuated completely fromcirculation pipe 21 also provokes a pressure drop aspirating a newquantity of water. Such a cycle can be reproduced as long as there iswater available in reservoir 1.

Connection column 3 presents in this example a bent form 3csubstantially inclined along axis x-x' with a length adapted to thevaporization cycles. In effect, the more substantial the bent form 3ccoming to be fixed on circulation pipe 21, the greater will be thequantity admitted into said circulation pipe 21. The quantity of steamproduced is increased as a result. The duration of each vaporizationcycle depends equally on the power of heating element 22.

The heating unit according to another form of construction according tothe present invention is associated with a pump permitting the pressureof the fluid to be increased. The pump is advantageously situateddownstream of water heater 20 to increase the pressure of thedistributed water. The pump, not shown in the figures or an additionalpumping device is particularly advantageous for the preparation ofespresso coffee. According to another form of construction according tothe present invention, the heating unit is arranged in a steam jetcleaning device or in a steam generator for a pressing iron.

The advantage of the heating unit according to the invention resides inits extreme simplicity as well as in its utilization permitting theproduction of either hot water or steam. It is thus no longerindispensable to utilize a specific water heater or anther device toproduce steam. The steam can be produced as long as there is water inreservoir 1, possibly in alternation with production and distribution ofhot water.

Another advantage to the heating unit according to the invention residesin the particular configuration of the water heater 20 permitting afirst evaporation phase in first part A not resulting in a firstexpulsion of hot water which has not achieved a sufficient temperature.The first vapor bubbles being displaced toward non-return valve 4, inthis first permitting to contain all of the water contained in the waterheater 20, in thermal exchange with heating element 22 in a manner toexpel said water only when it will have achieved a temperature greaterthan 90° C. A possible distribution of water not having achieved arequired temperature can only involve a small volume of water on the onehand, and can only concern the first water expulsion cycle on the otherhand. The portion of circulation pipe extending beyond the extremity ofheating element 22 of second part B equally prevents a premature coolingof water expelled from said water heater.

A supplementary advantage of the heating unit according to the inventionresides in the production of hot water at a temperature greater than 90°thus permitting in an application relative to a coffee maker obtaining afinished beverage, such as coffee at a higher temperature. Such animprovement in temperature easily permits the user to mix his beveragewith milk or another liquid at ambient temperature. Extraction is foundto be optimized by the same occasion with a temperature superior to 90°C., with very small operating noises and vapor phases.

A complementary advantage of the heating unit according to the inventionis the utilization of a single thermostat 30 for the hot water phase andthe steam phase. Utilization of the thermostat 30 permits cutting of thesupply of the heating element 22 when the temperature of the waterheater rises above a certain threshold. This latter is achieved ingeneral when all of the water contained in circulation pipe 21 and inreservoir 1 is evaporated. Deteriorations associated with overheatingare thus avoided, and in particular at the location of the connectionswith plastic or silicones elements, such as hoses for example.

The length portion C, which is not directly in contact with heatingelement 22, constitutes in addition a thermal brake or buffer withrespect to connection member 24, made for example, of silicone.

Moreover, the production of steam and the admission of cold water inalternation permits obtaining thermal shocks in water heater 20. Suchphenomena are found to be particularly advantageous to loosen or breakup layers of scale deposited at the interior of circulation pipe 21.

Possibilities of Industrial Application

The present invention finds its application in particular in appliancesfor preparation of hot beverages, of the electric coffee maker type.

What is claimed is:
 1. Heating unit for household appliance constitutedby a water circulation pipe (21) in thermal communication with a heatingelement (22) permitting the transfer of water contained in a reservoir(1) toward a distribution member (10), through, respectively, aconnection column (3) disposed below the reservoir (1) and thecirculation pipe (21) presenting a configuration in two parts (A, B)associated with a portion of the heating element (22), the second partrising to lead the water toward the distribution member (10),characterized in that the first part (A), oriented angularly withrespect to the second part (B), extends between the connection column(3) furnished with a non-return valve (4) and said second part (B), inan inclined and descending manner in the direction of flow of water, andthe distribution member (10) comprises a first orifice (11) allowingescape of hot water by gravity, and a second orifice (12) presenting astricture (12a) permitting production of steam starting from watercontained in the circulation pipe (21).
 2. Heating unit according toclaim 1 characterized in that the first part (A) extends along an axis(x-x') having an inclination with respect to its orthogonal projectionon a horizontal plane, greater than or equal to 4°.
 3. Heating unitaccording to claim 1 characterized in that the second part (B) extendsalong an axis (y-y') presenting an inclination with respect to itsorthogonal projection on a horizontal plane, said inclination beingcomprised between 45° and 135°.
 4. Heating unit according to claim 1characterized in that at least one of the parts (A, B) presents a curvedform defined by at least one radius of curvature.
 5. Heating unitaccording to claim 1 characterized in that the heating element (22)provides a uniform thermal yield along all of its length.
 6. Heatingunit according to claim 1 characterized in that the heating element (22)is in thermal communication with the circulation pipe (21) in the firstpart (A) on a proportion of length of the heating element (22) less thanthe proportion of length of the heating element (22) in thermalcommunication with the circulation pipe (21) in the second part (B). 7.Heating unit according to claim 6 characterized in that the distributionof thermal transfer between the heating element (22) and the circulationpipe (21) corresponds to values comprised between 35% and 45% in thefirst part (A) and values comprised between 55% and 65% in the secondpart (B).
 8. Heating unit according to claim 6 characterized in that thedistribution of thermal transfer between the heating element (22) andthe circulation pipe (21) corresponds, in the first part (A), to a valuecomprised between 20% and 30% of the total thermal transfer.
 9. Heatingunit according to claim 1 characterized in that it is constituted of twometallic tubes in thermal communication one of which constitutes thewater circulation pipe (21), the other metallic tube forming a housingfor the heating element (22).
 10. Heating unit according to claim 1characterized in that the distribution member (10) is constituted by agate capable of placing the circulation pipe (21) in communicationeither with the first orifice (11) or with the second orifice (12). 11.Heating unit according to claim 1 characterized in that the circulationpipe (21) comprises beyond the second part (B) a length portion (C)heated solely by thermal conduction by the second part (B).
 12. Heatingunit according to claim 1 characterized in that it is mounted on ahousehold appliance.
 13. Electric coffee maker comprising a heating unitaccording to claim
 1. 14. A heating unit according to claim 1 whereinsaid first part (A) is inclined downwardly, in the direction of flow ofwater, from said connection column (3).
 15. A heating unit according toclaim 14 wherein said first part (A) has an inlet end and an outlet end,and said water circulation pipe further includes a first curved portionconnected between said connection column (3) and said inlet end of saidfirst part (A) and a second curved portion connected between said outletend of said first part (A) and said second part (B).
 16. Heating unitaccording to claim 1 characterized in that the first part (A) extendsalong an axis (x-x') having an inclination, with respect to itsorthogonal projection on a horizontal plane, between 5° and 10°. 17.Heating unit according to claim 1 characterized in that the second part(B) extends along an axis (y-y') having an inclination, with respect toits orthogonal projection on a horizontal plane, between 45° and 100°.